1. Field of the Disclosure
Embodiments of the present disclosure generally relate to energy assisted magnetic recording (EAMR).
2. Description of the Related Art
In hard disk drives (HDDs), a magnetic head is disposed over a magnetic media. The magnetic head reads from, and writes data to, the magnetic media. The magnetic head has a surface, referred to as an air bearing surface (ABS), facing the magnetic media. As the magnetic media moves, air exerts a pressure on the ABS and pushes the magnetic head away from the magnetic media. The magnetic head is formed on a slider, which is coupled to a suspension. The suspension exerts a counter force that, when considered in concert with the moving media, ensures the magnetic head is disposed a predetermined distance from the magnetic media during operation.
In EAMR, the recording medium is locally heated to decrease the coercivity of the magnetic material during write operations. The local area is then rapidly cooled to retain the written information, which allows for conventional magnetic write heads to be used with high coercivity magnetic materials. The heating of a local area may be accomplished by, for example, a heat or thermal source such as a laser. One type of EAMR is heat assisted magnetic recording (HAMR). HAMR may also sometimes be referred to as thermally assisted magnetic recording (TAMR) or optically assisted magnetic recording (OAMR). EAMR is feasible to circumvent the limits of the magnetic recording areal density of perpendicular magnetic recording (PMR) technology, which is currently about 700-800 Gb/in2. EAMR is able to increase the areal density to beyond 1 TB/in2.
The energy in an EAMR head is directed from an energy source through the head by utilizing a waveguide and a near field transducer (NFT). The NFT coupled the diffraction limited light from a waveguide further focuses the light field energy beyond the diffraction limit of the waveguide down to a highly concentrated near field media heating spot. The NFT comprises plasmonic metals such as Au, Ag, Cu and their alloys. The plasmonic metals have a high density of free electrons and therefore are mechanically not very robust and thus susceptible to damage caused by thermal or mechanical stresses. Under those stresses, NFT failure is common.
Therefore, there is a need in the art for an improved EAMR head.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation. It is to be understood that all drawings are not to scale.